1. Field of the Invention
The present invention generally relates to multilayered conformal coatings of tunable, low electronic loss ceramic composites and method of production thereof. More particularly, the invention relates to a method of producing multilayered conformal coatings of tunable, low electronic loss ceramic composites wherein the method, preferably, comprises an electrophoretic deposition (EPD) method.
In accordance with the invention, ceramic composites of barium strontium titanium oxide (Ba0.60Sr0.40TiO3) and magnesium oxide (MgO) are used to produce multilayered conformal coatings of tunable, low electronic loss ceramic composites. However, other tunable, low loss ceramic composites can also be produced in the above-mentioned forms utilizing the method of the present invention.
2. Description of the Prior Art
The EPD method has been used to deposit ferroelectric ceramics and other materials. For example, U.S. Pat. No. 2,843,541 mentions the use of EPD for ferroelectric materials.
Since the issuance of that patent, the EPD method has been utilized successfully by other groups to deposit and produce devices for high temperature, super conducting materials, pyroelectric materials, and dielectric capacitors. For example, U.S. Pat. No. 4,952,557xe2x80x94Schmidt et al. and U.S. Pat. No. 5,262,026xe2x80x94Nojima et al. disclose the production of high temperature superconducting materials. U.S. Pat. No. 4,500,397xe2x80x94Mori et al. discloses the production of pyroelectric materials. Finally, U.S. Pat. No. 5,382,928xe2x80x94Davis et al. discloses the production of dielectric capacitors.
However, up to this point, there has not been a method of producing multilayered conformal coatings of tunable, low electronic loss ceramic composites, and more particularly the use of an EPD method to develop such multilayered conformal coatings. As disclosed in U.S. Pat. No. 5,427,988xe2x80x94Sengupta et al., composites of barium strontium titanium oxide and magnesium oxide have demonstrated electronic properties which are very useful for antenna applications. These properties include (but are not limited to) electronically variable dielectric constants and low loss of energy in the material. Furthermore, variations of these composites have also been demonstrated to have excellent pyroelectric properties for sensor applications.
Nevertheless, up to this point, there has not been a method which is both valuable and inexpensive in producing thick films of these materials such that they can be used for applications at frequencies which call for material thicknesses of one micron to several microns. Moreover, up to this point, the deposition conditions for such mutliphase composites have not been discovered or known.
The present invention generally relates to multilayered conformal coatings of tunable, low electronic loss ceramic composites and a method of production thereof. In particular, the invention relates to a method (specifically, an EPD method) for producing ceramic composites in an inexpensive manner to produce thick films of materials. Notably, the inventive method results in the deposition of material films of such thickness that they can be used in antenna or sensor applications, and can be used for applications of frequencies calling for material thickness of one micron to several microns. Finally, the invention is carried out under deposition conditions for multiphase composites, which deposition conditions are necessary in order to obtain the dielectric properties required for antenna and other tunable device applications.
The method of depositing conformal thin films of low loss materials basically comprises the steps of providing a base solution, mixing a multiphase composite powder with the base solution to obtain a mixed solution, inserting two sheet electrodes into the mixed solution, and applying a constant direct current (DC) bias voltage across the two sheet electrodes for a given period of time to deposit the conformal thin films of low loss materials. Preferably, the method is used to deposit the conformal thin films of low loss materials on an insulated substrate.
Therefore, it is a primary object of the present invention to provide multilayered conformal coatings of tunable, low electronic loss ceramic composites.
It is an additional object of the present invention to provide a method for producing such multilayered conformal coatings of tunable, low electronic loss ceramic composites.
It is an additional object of the present invention to provide ceramic composites of Ba0.60Sr0.40TiO3and MgO as tunable, low loss ceramic composites.
It is an additional object of the present invention to provide a valuable and inexpensive method for producing composites having excellent pyroelectric properties for sensor applications.
It is an additional object of the present invention to provide such components having electronic properties useful for antenna applications.
It is an additional object of the present invention to provide a method for producing thick film composites of materials such that they can be used for applications at frequencies which call for material thickness of one micron to several microns.
It is an additional object of the present invention to provide a method for producing multilayered conformal coatings having dielectric properties required for antenna and other tunable devices applications.
The above and other objects, and the nature of the invention, will be more clearly understood by reference to the following detailed description, the associated drawing, and the appended claims.